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Updated: Mar 13, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Microstructural brain abnormalities in medication-free patients with major depressive disorder: a systematic review
Jing Jiang1, You-Jin Zhao1, Xin-Yu Hu1
1From the Huaxi MR Research Center (HMRRC), Department of Radiology, Psychoradiology and Psychiatry, West China Hospital and Schools of Clinical Medicine, Sichuan University, Chengdu, China (Jiang, Zhao, Hu, Du, Chen, Wu, Li, Zhu, Gong); the Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China (Zhu); the Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, Mass., USA (Kumar); Department of Psychiatry, Harvard Medical School, Boston, Mass., USA (Kumar); the Department of Psychiatry, Yale University School of Medicine, New Haven, Conn., USA (Gong).
Background:
Multiple meta-analyses of diffusion tensor imaging (DTI) studies have reported impaired white matter integrity in patients with major depressive disorder (MDD). However, owing to inclusion of medicated patients in these studies, it is difficult to conclude whether these reported alterations are associated with MDD or confounded by medication effects. A meta-analysis of DTI studies on medication-free (medication-naive and medication washout) patients with MDD would therefore be necessary to disentangle MDD-specific effects.
Methods:
We analyzed white matter alterations between medication-free patients with MDD and healthy controls using anisotropic effect size-signed differential mapping (AES-SDM). We used DTI query software for fibre tracking.
Results:
Both pooled and subgroup meta-analyses in medication washout patients showed robust fractional anisotropy (FA) reductions in white matter of the right cerebellum hemispheric lobule, body of the corpus callosum (CC) and bilateral superior longitudinal fasciculus III (SLF III), whereas FA reductions in the genu of the CC and right anterior thalamic projections were seen in only medication-naive patients. Fibre tracking showed that the main tracts with observed FA reductions included the right cerebellar tracts, body of the CC, bilateral SLF III and arcuate fascicle.
Limitations:
The analytic techniques, patient characteristics and clinical variables of the included studies were heterogeneous; we could not exclude the effects of nondrug therapies owing to a lack of data.
Conclusion:
By excluding the confounding influences of current medication status, findings from the present study may provide a better understanding of the underlying neuropathology of MDD.
Insights
This study analyzed white matter integrity in medication-free individuals with major depressive disorder (MDD). Findings reveal significant fractional anisotropy reductions, suggesting MDD-specific neuropathology.
Area of Science:
- Neuroimaging
- Neuropsychiatry
- Brain Imaging Analysis
Background:
- Previous diffusion tensor imaging (DTI) meta-analyses suggest impaired white matter integrity in major depressive disorder (MDD).
- Confounding effects of medication in prior studies limit conclusions about MDD-specific alterations.
- A meta-analysis of DTI studies in medication-free MDD patients is needed to clarify neuropathology.
Purpose of the Study:
- To investigate white matter integrity in medication-free patients with MDD compared to healthy controls.
- To identify specific white matter tracts affected by MDD, independent of medication effects.
- To provide a clearer understanding of the neuropathological basis of MDD.
Main Methods:
- Utilized anisotropic effect size-signed differential mapping (AES-SDM) for meta-analysis.
- Employed DTI query software for detailed fiber tracking analysis.
- Included only medication-naive and medication washout patients to exclude current medication effects.
Main Results:
- Robust fractional anisotropy (FA) reductions observed in the right cerebellar lobule, corpus callosum (CC) body, and bilateral superior longitudinal fasciculus III (SLF III) in medication washout patients.
- FA reductions in the genu of the CC and right anterior thalamic projections were specific to medication-naive patients.
- Fiber tracking confirmed FA reductions in right cerebellar tracts, CC body, bilateral SLF III, and arcuate fascicle.
Conclusions:
- Excluding medication effects provides a clearer view of MDD-related white matter alterations.
- Findings suggest specific white matter tract abnormalities are associated with MDD.
- This study contributes to understanding the neuropathology of major depressive disorder.
